<!DOCTYPE html>
<html lang="zh">
	<head>
		<meta charset="UTF-8">
		<meta name="viewport" content="width=device-width, initial-scale=1.0">
		<meta http-equiv="X-UA-Compatible" content="ie=edge">
		<title></title>
		<style type="text/css">
			div{
				float: left;
				width: 50px;
				height: 50px;
				background-color: orange;
				margin: 50px;
				box-shadow: 0 0 0 8px green,
							0 0 0 16px blue,
							0 0 0 24px red;
							
			}
			.box1{
				border-radius: 100%;
			}
		</style>
	</head>
	<body>
		<div class="box1"></div>
		<div class="box2"></div>
	</body>
</html>
